The coaxial connector of the invention is usable in particular for making a front face connection with radio frequency (RF) modules located in an equipment bay of a base station.
In this application, the RF modules can be transmitter modules or receiver modules, for example, each comprising a printed circuit card having passive and active RF components mounted thereon interconnected by RF transmission lines formed on the printed circuit.
The RF modules are connected to one another by coaxial cords, and for this purpose each module has one or more coaxial connectors secured in the vicinity of an edge of the printed circuit card.
In order to avoid disturbing the external environment with parasitic electromagnetic emissions, each module is generally provided with its own electromagnetic shielding, firstly in order to prevent parasitic electromagnetic emissions associated with the radiation generated by the RF components within the module, and secondly to enable the module to operate properly without itself being disturbed by parasitic electromagnetic emissions coming from the outside.
Ensuring that the module is electromagnetically shielded requires the connectors on the front face to perform an electrical continuity function between the ground of the connector and the frame of the module.
Traditionally, this function has been implemented by a screw-and-nut system in the connector.
However, it is difficult to ensure electrical continuity between the frame and the various elements that pass through it, and at present the trend is towards limiting electromagnetic shielding to those sources of radiation that are situated on the printed circuit, i.e. the transmission lines and the passive and active RF components.
The shielding function is then provided by caps covering the various sources of radiation other than the coaxial connectors, since these are difficult to integrate.
As a result, the RF transmission lines interconnecting the circuit components to the connector need to be optimized in order to minimize radiation.
That requires the use of single-layer printed circuits and the use of plated-through holes in order to ground the RF lines (microstrips or strip lines). That has the drawback of generating additional RF losses.